U.S. patent number 5,327,653 [Application Number 07/932,302] was granted by the patent office on 1994-07-12 for miter linear measurement gage.
Invention is credited to Thomas H. Hoffmann, Robert T. Pistorius.
United States Patent |
5,327,653 |
Pistorius , et al. |
July 12, 1994 |
Miter linear measurement gage
Abstract
A magnetic-electronic linear measurement gage for measuring
workpiece miter lengths for picture and window frames and the like
includes a gage bed on which a workpiece may be removably mounted,
a stop body slidably mounted on the gage bed having a stop which
may butt against a workpiece mitered end, and length and width
scales and scanning units associated with the gage and the stop
body generating output signals in response to the scanning of the
scales. The output signals are received and converted by a CPU to
generate a linear measure output signal which may be inputted to a
digital LED display for visually displaying the linear measure
corresponding to the workpiece length so measured.
Inventors: |
Pistorius; Robert T. (Lake
Ronkonkoma, NY), Hoffmann; Thomas H. (7520 Bruchsal,
DE) |
Family
ID: |
25462110 |
Appl.
No.: |
07/932,302 |
Filed: |
August 19, 1992 |
Current U.S.
Class: |
33/1M; 33/526;
33/708; 83/522.25 |
Current CPC
Class: |
B23D
47/04 (20130101); B23D 59/001 (20130101); B23Q
3/007 (20130101); B26D 7/01 (20130101); B26D
7/28 (20130101); B27B 27/02 (20130101); G01D
5/145 (20130101); Y10T 83/863 (20150401) |
Current International
Class: |
B23D
47/00 (20060101); B23Q 3/00 (20060101); B23D
47/04 (20060101); B23D 59/00 (20060101); B26D
7/00 (20060101); B26D 7/28 (20060101); B26D
7/01 (20060101); B27B 27/00 (20060101); B27B
27/02 (20060101); G01D 5/12 (20060101); G01D
5/14 (20060101); G01B 007/02 (); B26D 007/28 () |
Field of
Search: |
;33/706,707,708,784,526,464,466,1M
;83/522.18,522.19,522.21,522.25 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Cuchlinski, Jr.; William A.
Assistant Examiner: Wirthlin; Alvin
Attorney, Agent or Firm: Galgano & Burke
Claims
What is claimed is:
1. A linear measurement gage for measuring workpiece miter lengths
and inside dimensions for picture and window frames and the like,
comprising:
an elongated gage bed having an upright fence on which a workpiece
may be removably mounted abutting said fence;
stop means slidably mounted on said gage bed having a stop which
may butt against a workpiece mitered end and whose position may be
fixed to fix the position of said workpiece, said stop means having
a transverse leg coupled thereto disposed transversely to said gage
bed which has an extensible and retractable arm slidably secured
thereto;
length scale and scanning means having an incremental linear length
scale and a length non-contacting scanning unit for scanning said
incremental linear length scale, one of said length scale means and
said lengthscanning unit being mounted on said bed and the other
being mounted on said stop means, said scanning unit generating
length output signals in response to the scanning of said
scale;
width scale and scanning means having an incremental linear width
scale and a width non-contacting scanning unit for scanning said
incremental linear width scale, one of said width scale means and
said width scanning unit being mounted on said stop means in a
direction transverse to said bed and the other being movably
mounted relative thereto, said width scanning unit generating width
output signals in response to the scanning of said width scale,
said width scale and scanning means including a reference switch
for generating a reference signal relative to the position or width
being measured;
computer control means for receiving the length and width output
signals, and for converting said output signals to a linear measure
output signal corresponding to the inside dimension of the
workpiece being measured; and
display means for displaying said measured inside dimension of the
workpiece coupled to said computer control means.
2. The linear measurement gage according to claim 1 wherein said
length and width incremental linear scales are linear magnetic
pulsing scales having successive, reversely-polarized, spaced-apart
scale elements, with said length scale being mounted on said gage
bed, and said width scale being mounted on said transverse leg of
said stop means.
3. The linear measurement gage according to claim 2, wherein said
length and width scanning units each comprise a pair of hall effect
magnetic sensors, said pair of said length scanning unit being
mounted on said pair of said width scanning unit being mounted on
said extensible and retractable arm of said stop means transverse
leg.
4. The linear measurement gage according to claim 1, wherein said
display means comprises a digital LED display.
5. The linear measurement gage according to claim 1, wherein said
stop means is slidably mounted on said gage bed fence and has a
rotatable control knob which is engagable with said fence to fix
the position of said stop means.
6. The linear measurement gage according to claim 5, wherein said
gage bed fence has a C-shaped cross-section.
7. The linear measurement gage according to claim 1, wherein said
retractable arm has an upstanding shaft mounted thereon which, in
turn, telescopically supports an upstanding and vertical
displaceable handle grip.
8. The linear measurement gage according to claim 7, wherein said
handle grip has an inwardly-directed, horizontally-extending tongue
secured thereto and a push button electrical switch mounted thereon
which serves as said reference switch.
9. A linear measurement gage for measuring workpiece miter lengths
and inside dimensions for picture and window frames and the like,
comprising:
an elongated gage bed having an upright fence on which a workpiece
may be removably mounted abutting said fence;
stop means slidably mounted on said gage bed having a stop which
may butt against a workpiece mitered end and whose position may be
fixed to fix the position of said workpiece, said stop means having
a transverse leg coupled thereto disposed transversely to said gage
bed which has an extensible and retractable arm slidably secured
thereto;
length scale and scanning means having an incremental linear length
scale and a length non-contacting scanning unit for scanning said
incremental linear length scale, said scanning of said scale, and
linear length scale being a linear magnetic pulsing scale having
successive, reversely polarized, spaced-apart scale elements, with
said linear scale being mounted on said gage bed, and said length
scanning unit comprises a pair of hall effect magnetic sensors
mounted on said stop means for travel therewith along said gage
bed;
width scale and scanning means having an incremental linear width
scale and a width non-contacting scanning unit for scanning said
incremental linear width scale, and width scanning unit generating
width output signals in response to the scanning of said width
scale, said width scale and scanning means including a reference
switch for generating a reference signal relative to the position
or width being measured, said linear width scale being a linear
magnetic pulsing scale having successive, reversely polarized,
spaced-apart scale elements, with said width scanning unit
comprises a pair of hall effect magnetic sensors mounted on said
extensible and retractable arm of said stop means transverse
leg;
computer control means for receiving the length and width output
signals, and for converting said output signals to a linear measure
output signal corresponding to the inside dimension of the
workpiece being measured; and
display means for displaying said measured inside dimension of the
workpiece coupled to said computer control means.
10. The linear measurement gage according to claim 9, wherein said
handle grip has an inwardly-directed, horizontally-extending tongue
secured thereto and a push button electrical switch mounted thereon
which serves as said reference switch.
Description
BACKGROUND OF THE INVENTION
The present invention relates to an improved gage for measuring the
length of mitered articles, especially inside and outside lengths
of 45 degree miters. More particularly, it relates to such a gage
for measuring and sizing mitered lengths for picture frames,
windows and the like.
In the manufacture of picture frames, it is generally necessary to
join together mitered lengths of frame stock, typically made of
wood, metal or plastic or a composite thereof. Standard frames are
square or rectangular and require four mitered lengths which form
the four sides of the frame. These frame lengths must be accurately
mitered to ensure proper sizing and fit of the subsequently joined
lengths. The frame side lengths are typically cut with a double
bladed miter saw. Mechanical gages have been employed to measure
the lengths prior to cutting.
One commercial example of a mechanical gage is the VISI-MITER gage
sold by Pistorius Machine Co., Inc., of Hauppauge, New York,
covered by U.S. Design Pat. No. 224,717. The gage allows one to
easily and without computations measure either inside, rabbet or
outside "tip-to-tip" dimensions to suit the size of the item being
framed. The gage includes a stainless steel gage strip having a
scale comprised of etched and color-coded visual sighting lines
which are parallel to the saw blade on the right hand side of the
double miter saw. When material to be measured is placed on the
stainless scale, the mitered face of the material is at right
angles to the visual sighting lines. If the rabbet dimension is
desired, the operator places the rabbet corner of the molding
directly on the sighting line for the dimension desired. A stop is
then placed against the miter and tightened with a handle. The
operator can then repetitively cut accurate lengths of stock simply
by placing the stock against the stop. For each change of size
required, the above process must be repeated.
While quite satisfactory in use, the accuracy of the gage is
limited by the visual accuracy of the operator, which can vary from
piece to piece or operator to operator.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a
novel linear measurement gage which specifically intended for
picture and window frames and the like which eliminates inaccurate
measurements caused by visual sighting errors.
It is a further object of the present invention to provide an
electronic digital linear measurement gage for outside, inside and
rabbet measurements which will allow virtually any operator to make
error free stop settings, improve quality control, and virtually
eliminate incorrectly cut parts.
It is yet a further object of the present invention to provide such
an electromechanical gage which is readily adaptable to fit a wide
variety of commercial saw machinery and, in particular, double
miter saws which quickly affords digital readouts in fractions,
either English decimals, or Metric (millimeters) measurements with
a high degree of accuracy and resolution.
It is a more particular object of the present invention to provide
a novel magnetic-electronic linear measurement gage which is
relatively simple in design, economical to fabricate and easy to
use.
Certain of the foregoing and related objects are readily attained
in a linear measurement gage for measuring workpiece miter lengths
for picture and window frames and the like comprising an elongated
gage bed having an upright fence on which a workpiece may be
removably mounted abutting the fence and stop means slidably
mounted on the gage bed having a stop which may butt against a
workpiece mitered end and whose position may be fixed to fix the
position of the workpiece. A length scale and scanning means is
also provided having a first incremental linear scale and a first
length non-contacting scanning unit for scanning said incremental
linear scale, with one of the scale means and the scanning unit
being mounted on the bed and the other being mounted on the stop
means, the scanning unit generating first output signals in
response to the scanning of the scale. The device further includes
width scale and scanning means having a second incremental linear
scale and a second length non-contacting scanning unit for scanning
the incremental linear scale, with one of the scale means and the
scanning unit being mounted on the stop means in a direction
transverse to the bed and the other being movably mounted relative
thereto, the second scanning unit generating second output signals
in response to the scanning of the second scale. Display means are
provided for displaying the measured length of the workpiece. The
device additionally includes computer control means for receiving
the first and second output signals, deriving from the output
signals, digital countable signals and a direction signal
indicating the direction of the scanning movement, counting and
converting the countable and directional signals to a linear
measure output signal which may be inputted to the display means
for visually displaying the linear measure corresponding to the
workpiece length so measured.
Preferably, the stop means has a transverse leg coupled thereto
disposed transversely to the gage bed which has an extensible and
retractable arm slidably secured thereto. In a particularly
preferred embodiment of the invention, the first and second
incremental linear scales are linear magnetic pulsing scales having
successive, reversely-polarized, spaced-apart scale elements, with
the first scale being mounted on the gage bed, and the second scale
being mounted on the transverse leg of the stop means. Most
advantageously, the first and second scanning units each comprise a
pair of hall effect magnetic sensors, the pair of the first
scanning unit being mounted on the stop means for travel therewith
along the gage bed and the pair of the second scanning unit being
mounted on the extensible and retractable arm of the stop means
transverse leg. Most desirably, the width scale and scanning means
includes a reference switch for generating a reference signal
relative to the position or width being measured.
The display means preferably comprises a digital LED display. In
addition, the stop means is desirably slidably mounted on the gage
bed fence and has a rotatable control knob which is engagable with
the fence to fix the position of the stop means. The gage bed fence
advantageously has a C-shaped cross-section.
In a particularly preferred embodiment of the invention, the
retractable arm has an upstanding shaft mounted thereon which, in
turn, telescopically supports an upstanding and vertical
displaceable handle grip. The handle grip has an inwardly-directed,
horizontally-extending tongue secured thereto and a push button
electrical switch mounted thereon which serves as said reference
switch.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become
apparent from the following detailed description considered in
connection with the accompanying drawings which discloses one
embodiment of the present invention. It should be understood,
however, that the drawings are designed for the purpose of
illustration only and not as a definition of the limits of the
invention.
In the drawings, wherein similar reference characters denote
similar elements throughout the several views:
FIG. 1 is a front and top isometric view of the linear measurement
gage embodying the present invention disposed adjacent a
conventional double miter saw;
FIG. 2 is a rear and top isometric view of the linear measurement
gage embodying the present invention;
FIG. 3 is a side sectional view of the inventive gage showing a
molding length being measured by the gage and showing the vertical
and horizontal adjustment of the rabbet width measuring arm, in
phantom line.
FIG. 4 is a front elevational view of the inventive gage;
FIG. 5 is a bottom view of the inventive gage; and
FIG. 6 is a plan and sectional view of a molding length showing the
standard length dimensions to be measured by the gage;
FIG. 7 is an isometric view of a conventional picture frame;
and
FIG. 8 is an isometric view of a typical double hung window and
frame.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now in detail to the drawings, and in particular, FIGS. 1
and 2 thereof, their illustration is a novel linear measurement
gage embodying the present invention which includes an elongated
rail or gage bed preferably made of nickel plated steel, generally
designated 10, having a horizontal leg 11 for supporting mitered
lengths of workpiece stock 60 and a vertical leg or fence 12 having
a C-shaped cross-section which slidably supports a linear scale
reader and display assembly, generally designated 20. Support rail
10 is suitably supported by support legs 9 (see FIG. 4) adjacent to
a conventional double miter saw generally designated 14, having two
cooperating saw blades 15 oriented to provide a double miter cut in
stock 60.
As seen best in FIGS. 3 and 5, a linear magnetic pulsing scale 16
(represented in part by phantom line in FIG. 5) is placed on the
underside of bed 11 of rail 10 and extends most of its entire
length. Magnetic scale 16 preferably has a multiple-ply sandwich
construction composed of an inner ply (0.3 mm) of a magnetized
flexible steel strip, a middle ply of ferrite-bonded or impregnated
flexible plastic strip (1.2 mm) and an outer ply (0.3 mm) of
stainless steel strip, which serves as a protective shield. The
ferrite-bonded flexible plastic has a multiplicity of spaced-apart
magnetic scale elements or reference bars, with adjacent bars
having a reverse polar orientation, preferably spaced apart 5 mm
(200 poles/m), with the bars being transversely oriented relative
to rail 10. The purpose and operation of the magnetic scale 16 will
be discussed in greater detail hereinafter.
As shown in FIGS. 1-3, the scale reader and display assembly 20
includes a movable support and stop body 21, having an extended
stop tongue 22 at the end thereof proximate to saw 14 and at its
opposite end, a depending support body 23, the lower end of which
supports an inwardly directed sensor head of a pair of conventional
hall effect magnetic readers or sensors 24 disposed immediately
beneath magnetic scale 16; the purpose of the readers will be
discussed in greater detail hereinafter. Stop body 21 slidably
rests on a low friction slide 25 (see FIG. 3) to allow body 21 to
slide and reciprocate freely in both directions along C-shaped
fence 12. Stop body 21 has a threadably supported, conventional
rotatable control knob 26 which can be used to lock stop body 21
via its shaft 27 which presses a stop block 28 against gage fence
12 at a desired position. Immediately behind and above control knob
26 is a display housing 29 supported on stop body 21 which houses
an LED digital read out display 13 for displaying the length
measured.
A material or stock width magnetic sensor and reader assembly 31 is
also attached to stop body 21 on the rear side of gage bed 11 such
that it is positioned outwardly of stop tongue 22 so that it will
face the stock 60 along its normal width, i.e., spaced from its
mitered end 62 (see FIG. 5). As seen best in FIG. 3, the assembly
31 includes a horizontal support or leg 32 affixed to stop body 21
which protrudes transversely beneath gage bed 11 and which slidably
supports a stock width measuring arm, generally designated 35,
which has a retractable horizontal leg 36 which is spring loaded
via spring 37 held at one end by a pin 33 to leg 32 and at its
other end by a pin 34 to leg 36 and slidably supported via support
32. A linear magnetic pulsing scale 38 (See FIG. 5), similar to
scale 16, is affixed to the underside of leg 36 and extends
substantially its entire length. Stop body 21 has a depending
support body 39 which supports a material width sensor head of a
pair of conventional hall effect magnetic sensors or readers 40
immediately beneath scale 38.
An upright, cylindrical grip handle 41 having a soft rubber grip is
mounted on the end of leg 36 such that it is vertically
displaceable. Handle 41 is telescopically received in a slight
friction-fit manner on lower inner shaft 42 to allow for vertically
displaceable movement of handle 41. An inwardly and
horizontally-extending width sensor tongue 43 is affixed to the
lower end of handle 41, the tip 44 of which serves to engage the
stock 60 at a rabbet joint 63. As shown in phantom view in FIG. 3,
grip handle 41 can adjust vertically and horizontally (see arrows)
to accommodate different sizes, widths and rabbets of stock 60. The
grip handle also has a data entry push button electrical switch 45,
the purpose of which will be described in greater detail
hereinafter.
As shown in FIGS. 4 and 5, the electrical outputs from the length
magnetic readers are coupled via wire leads 50 to an input of a
conventional microprocessor-based control unit 70 comprising a
central processing unit or CPU which has an on/off switch 72 and a
data entry keypad 74. Similarly, the magnetic width sensors and
push button switch 45 are also coupled to microprocessor-based
control unit 70 via wire leads 52. The output of control unit 70 is
coupled via wire lead 58 to the LED display 13.
FIG. 6 illustrates the standard dimensions of the workpiece stock
to be measured and the formula used by the CPU of the control unit
70 for determining rabbet length based on the desired tip-to-tip
length and base width for a 45.degree. miter cut-namely, C=B-2A
where A is the base width, B is the tip-to-tip dimension and C is
the rabbet or inside dimensions. The control unit CPU has a
computer logic chip which is equipped with a program which
mathematically calculates the difference between outside and inside
length via the above formula. Tip-to-tip length B can be determined
by transposing the equation to solve for B-namely, B=C+2A. These
calculations are suitable for making miter cuts for picture frames
80 (FIG. 7) and window frames 90. However, it can, of course, be
used for other miter angles so as to make other frame
configurations such as pentagons, octagons, etc. In such a case,
the formula would be C=B-2A/TAN.alpha. where .alpha. is the desired
miter angle.
The present electronic rabbet measurement gage displays both
tip-to-tip size measurements and rabbet size measurements for the
gaging of various materials. Tip-to-tip gaging is done by
electronically computing the distance of the gage stop from a known
reference point; this reference point is set by the push of button
45. The rabbet size gaging is done by electronically computing the
width of the material at which the gaging will be done for a piece
of material and then electronically computing what the rabbet size
would be based upon the material width, the tip-to-tip size, and
the angle of cut.
The material width and tip-to-tip sizing is determined through the
use of the two separate linear measuring devices. As previously
noted, both the length and width linear measuring devices are made
up of two conventional hall effect magnetic sensors mounted in a
sensor head that moves in a non-contacting fashion over the
magnetic scales 16 and 38 composed of discrete magnetized segments
or stripes with alternating "North" and "South" poles. As one of
the hall effect sensors passes over one of the magnetically
polarized sections of the ferrite strip, a varying voltage output
signal is given. From the varying output voltage, the position of
the sensor head can be determined relative to one of the polarized
sections. The varying voltage "steps" or pulses can then be relayed
via lines 50 and 52 counted via the CPU of the control unit as the
heads pass over one alternating polarized field to the next on the
ferrite strip. The number of "steps" can then be directly converted
into a distance based upon the known spacing of the magnetic
stripes or voltage "steps", e.g., with 5 mm spacings between
magnetic stripes, for every 0.1 mm of movement the CPU will count
one digital pulse By using the second hall effect sensor offset
from the first, direction of movement can be determined by the
relative changing voltages of each sensor. The CPU will then send a
signal to the LED display to digitally display the length defined
by the pulses counted. The actual operation and set up of the
control unit and sensors and its elements, i.e., magnetic hall
effect sensors, CPU will be well understood by those skilled in the
art as they concern standard conventional electronic components.
See, for example, U.S. Pat. Nos. 4,459,749, 4,631,403, 4,867,568,
4,982,507, 4,996,778, 5,007,177, 5,010,655, 5,021,650, 5,079,850,
5,099,583, 5,115,573 and 5,117,376, the subject matter of which is
incorporated herein by reference thereto.
Turning now to the operation of the gage, the operator initially
lays the material or stock 60 to be cut onto the bed 11 of the gage
10 against the fence 12. If a rabbet dimension is desired, the tip
44 of rabbet tongue 43 is slid in toward the fence 12 until it
contacts the molding 60 in the appropriate rabbet 63 (see FIG. 3).
After contact is made, the input button 45 on the top of the handle
41 is pressed, which inputs the position data to the CPU of the
control device via the magnetic scale 38 and sensor heads and the
rabbet length is instantly displayed on the digital display 13. If
tip-to-tip size is desired, the operator slides the "rabbet" sensor
tongue 43 to the gage fence 12 and presses the input button 45. The
digital display will then show the tip-to-tip length. Using the
keypad 74, the operator can select a display mode in decimals,
millimeters or fractions. In the fractional mode, delineations can
be selected fin 64ths, 16ths, 8ths, etc.
After the width of the molding has been entered, the operator
slides the stop body 21 left or right along the gage fence until
the LED digital display 13 shows the size desired. The control knob
26 on the stop body 21 is then tightened to maintain the selected
size in repetitive cuts. A battery backup is provided in the
control unit 70 for the CPU. As a result, when the unit is turned
on, the display will show the current position. The stop position
therefore does not need to be recalibrated when powered off. The
display is provided to allow accurate digital size positioning. The
CPU keypad 74 also allows initial calibration of the stop body 21
in relation to the saw blade, to compensate for different saw blade
kerf thicknesses, to compensate for glass allowance and to select
display mode (fractions, decimals or millimeters).
As can be seen from the foregoing, the present invention affords a
linear gage adaptable to both English and Metric scales. It is
therefore ideal for use anywhere in the world since display modes
can be changed instantly. It can be easily used by unskilled labor
with virtually no training. It provides repetitive accuracy
impossible to achieve with a mechanical gage. It can be set up for
either left or right hand use, and can be used for different
angles. It virtually eliminates operator error and is readily
adaptable to most machines.
It will be apparent that various modifications may be made as will
be apparent to those skilled in the art. For example, although the
electronic gage is designed for use on double miter saws, however
its use can be extended to single blade saws and the like.
Moreover, while the gage is designed primarily for 45 degree
angles, it can also be extended to other angles such as 22-1/2
degrees (octagon), 30 degrees (hexagon), etc.
In addition, although a magnetic sensing device is preferred, other
contactless sensing devices and increment encoders (i.e., position
verification devices that indicate linear motion and direction of
movement), preferably quadrative encoders to allow determination of
direction, could be employed such as optical encoders and scanning
units.
Accordingly, while only one embodiment of the present invention
have been shown and described, it is to be understood that many
changes and modifications may be made thereunto without departing
from the spirit and scope of the invention as disclosed herein.
* * * * *